Password Strength Checker

Check password length and character variety locally. Your password stays in this browser.

Preparing tool…

Guided walkthrough

Explore a simplified password-strength estimate.

Use only the public dummy text DemoOnly123!, never a real credential.
Compare the displayed length, search-space estimate, and indicative duration. Do not enter a real password for this demonstration.

Illustrative example

Compare DemoOnly123! with the same public text plus one extra character; neither is a password recommendation.

How to read the result

This simplified model assumes uniformly random choices from detected character groups. It does not account for predictable patterns or leaked passwords. The duration uses 10 billion guesses per second over the full modeled space; it is not a forecast of a real attack.

This is a static educational walkthrough. It does not fill fields, generate values, inspect your browser, or read storage. Use fictitious, non-secret data for practice. Never share passwords, keys, tokens, or cookie values. These explanations are not a security audit or certification.

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Quick answer

Check a password’s length, detected character groups, and simplified guessability estimate in your browser. The estimate is educational, not a security guarantee.

The page and its assets load from the site; this operation uses your entered values only in this browser and does not send them to a calculation endpoint.

How to use it

Enter a password to see its length, an estimated entropy value, and a rough exhaustive-search time. The estimate assumes random selection and a fixed guessing rate; real attacks use leaked passwords and patterns, so the number is not a security guarantee.

Limits

This page does not compare the password with breached-password lists or the rules of a particular service. Its estimate cannot predict an attacker’s method or hardware.

Frequently asked questions

Does the checker compare against leaked passwords?

No. It evaluates the entered value using the checks shown on the page; it does not query breach databases or a particular service’s password rules.

Why can a complex-looking password still be weak?

People often choose familiar words, dates, and patterns. A simple character-set estimate does not model those choices or password reuse.

Is the estimate a guarantee?

No. The bar is only this simplified search-space estimate and fills at 128 bits; it is not a universal strength rating. Attack methods, password reuse, rate limits, and the target’s password storage method change the real risk.

Why can emoji or accented text affect the estimate?

The displayed length counts JavaScript UTF-16 code units, not visible characters, so one emoji may count as two. The model recognizes ASCII letters and digits; every other character is treated as one of 33 possible symbols. Treat the estimate as rough for non-ASCII text.

Sources and references

These references document the cited standard or browser API; they do not validate the tool’s output.